# Mutation testing setup (/testing--mutation-testing)

/testing--mutation-testing is a Claude Code skill in the Code section. Sets up mutation testing to measure whether your tests would catch real bugs, then turns surviving mutants into stronger tests.

- Web version: https://skills.sgomez.dev/en/s/testing--mutation-testing
- Section: [Code](https://skills.sgomez.dev/en/code.md)
- Author: Santiago Gómez de la Torre
- License: MIT
- Source: https://github.com/sgomez-dev/claude-skills/blob/main/skills/testing/mutation-testing.md
- Updated 10 Jul 2026

## How to ask for it

- `/testing--mutation-testing set up mutation testing on my project`
- `/testing--mutation-testing why are so many mutants surviving in this module?`
- `/testing--mutation-testing harden tests that miss these mutations`

## Install

macOS · Linux:

```
curl -fsSL https://raw.githubusercontent.com/sgomez-dev/claude-skills/main/install.sh | bash
```

Windows:

```
irm https://raw.githubusercontent.com/sgomez-dev/claude-skills/main/install.ps1 | iex
```

Claude Code plugin:

```
/plugin marketplace add sgomez-dev/claude-skills
/plugin install testing-skills@claude-skills-collection
```

## Permissions

- Reads: `**/*`
- Writes: `**/*.test.*`, `**/*.spec.*`, `**/*_test.*`, `stryker.conf.*`, `stryker.config.*`, `infection.json*`, `mutmut_config*`, `setup.cfg`, `pyproject.toml`, `pom.xml`, `build.gradle*`, `package.json`, `.github/workflows/**`
- Runs: `npm`, `npx`, `yarn`, `pnpm`, `pytest`, `mutmut`, `cargo`, `mvn`, `gradle`, `dotnet`, `go test`
- Network: No
- Destructive: No

## Author's description

Set up mutation testing, interpret surviving mutants, and harden weak tests

- [How we review this](https://skills.sgomez.dev/en/methodology.md)